A new article, published recently in Nature Neuroscience, has reported the first known connection between noradrenergic neurons and individual vulnerability to depression. The findings highlight potential new opportunities for the development of depression treatments that may target the adrenergic system.

Researchers believe that responses to stressful life events are dictated by an individuals’ resilience, or their capacity to rebound from the event. However, how the concept of resilience works has yet to be uncovered.

The team mimicked stressful life events in animal models and by utilizing pharmacological, genetic and optogenetic approaches, confirmed that increases in dopaminergic neuron activity were linked to depression onset.

“We know that a small cerebral structure, known as the ventral tegmental area, contains dopaminergic neurons that play a key role in vulnerability to depression,” explained lead author Bruno Giros (McGill University; QC, Canada).

In addition to this, the study indicated that noradrenergic neurons, which are known to be linked to emotional regulation, sleep and mood disorders due to their use of noradrenaline, are also responsible for the control of dopaminergic neuron activity.

“It is this control that steers the body’s response toward resilience or toward vulnerability to depression,” remarked Giros.

Importantly the research also demonstrated that animal models unable to release noradrenaline are more vulnerable to depression following chronic stress, however this effect was reversible through increasing noradrenaline production, indicating potential applications for drug development.

“Beyond this discovery about the brain mechanisms involved in depression, our results help explain how adrenergic drugs may work and could be used to treat major depression,” commented Giros.